Config::MVP::Assembler is a helper for constructing a Config::MVP::Sequence object.
It's a very simple state machine that lets you signal what kind of events you've encountered while reading configuration.

This method tells the assembler that it should begin work on a new section with the given identifier. If it is already working on a section, an error will be raised. See "change_section" for a method to begin a new section, ending the current one if needed.

The package moniker is expanded by the "expand_package" method. The name, if not given, defaults to the package moniker. These data are used to create a new section and the section is added to the end of the sequence. If the package argument is a reference, it is used as the literal value for the package, and no expansion is performed. If it is a reference to undef, a section with no package is created.

This method tells the assembler that it has encountered a named value and should add it to the current section. If there is no current section, an exception is raised. (If this is not the first time we've seen the name in the section and it's not a multivalue property, the section class will raise an exception on its own.)

This method is passed a short identifier for a package and is expected to return the full name of the module to load and package to interrogate. By default it simply returns the name it was passed, meaning that package names must be given whole to the change_section method.

When changing sections, the given section "moniker" is used for the new section name. The result of passing that moniker to the assembler's "expand_package" method is used as the section's package name. (By default, this method does nothing.) The new section's multivalue_args and aliases are determined by calling the mvp_multivalue_args and mvp_aliases methods on the package.